1. Field
One or more embodiments relate to a speech processing apparatus and method which automatically control gain of a microphone.
2. Description of the Related Art
Recently, as consumer's demands of speech recognition increase, robot products equipped with microphones have been developed and have come onto the market. When speech detected by a speech sensor has an audible frequency band or a high frequency band, a robot having a speech recognition sensor performs a single operation as directed by the speech.
A speech recognition means of a robot includes a microphone to which fixed gain or automatic gain is applied, a buffer to store speech source data which is input through the microphone, and a speech processor to process the stored speech source data. The robot operates according to speech recognition.
Meanwhile, the loudness of speech which is input to the microphone is determined by the distance between the microphone and a speaker and by the loudness of a speaker's voice. Most microphones adjust gain according to the distance between the microphones and speakers. However, since speakers tend to speak quietly when close to the microphone and tend to speak loudly when distant from the microphone, adjusting the gain based on distance alone may be problematic. That is, the adjustment of gain according to the distance between a microphone and a speaker has a problem in that it does not consider the volume of the speaker's voice.